Measuring picometre-level displacements using speckle patterns produced by an integrating sphere
MetadataShow full item record
As the fields of optical microscopy, semiconductor technology and fundamental science increasingly aim for precision at or below the nanoscale, there is a burgeoning demand for sub-nanometric displacement and position sensing. We show that the speckle patterns produced by multiple reflections of light inside an integrating sphere provide an exceptionally sensitive probe of displacement. We use an integrating sphere split into two equal and independent hemispheres, one of which is free to move in any given direction. The relative motion of the two hemispheres produces a change in the speckle pattern from which we can analytically infer the amplitude of the displacement. The method allows a noise floor of 5 pm/√Hz (λ/160, 000) above 30 Hz in a facile implementation, which we use to measure oscillations of 17 pm amplitude (λ/50, 000) with a signal to noise ratio of 3.
Facchin , M , Bruce , G D & Dholakia , K 2023 , ' Measuring picometre-level displacements using speckle patterns produced by an integrating sphere ' , Scientific Reports , vol. 13 , 14607 . https://doi.org/10.1038/S41598-023-40518-6
Copyright © The Author(s) 2023. Tis article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
DescriptionFunding: The authors acknowledge funding from Leverhulme Trust (RPG-2017-197), UK Engineering and Physical Sciences Research Council (EP/P030017/1, EP/R004854/1) and Australian Research Council (FL210100099).
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.